From bf513fd6fc609590b7835c0dba624ccb9f8f9214 Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Tue, 13 Oct 2015 13:42:56 +0200 Subject: [PATCH] 6lowpan: introduce LOWPAN_IPHC_MAX_HC_BUF_LEN This patch introduces the LOWPAN_IPHC_MAX_HC_BUF_LEN define which represent the worst-case supported IPHC buffer length. It's used to allocate the stack buffer space for creating the IPHC header. Signed-off-by: Alexander Aring Acked-by: Jukka Rissanen Signed-off-by: Marcel Holtmann --- include/net/6lowpan.h | 8 ++++++++ net/6lowpan/iphc.c | 2 +- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h index 07db532696df..aa5a82380e4e 100644 --- a/include/net/6lowpan.h +++ b/include/net/6lowpan.h @@ -64,12 +64,20 @@ #define EUI64_ADDR_LEN 8 #define LOWPAN_NHC_MAX_ID_LEN 1 +/* Maximum next header compression length which we currently support inclusive + * possible inline data. + */ +#define LOWPAN_NHC_MAX_HDR_LEN (sizeof(struct udphdr)) /* Max IPHC Header len without IPv6 hdr specific inline data. * Useful for getting the "extra" bytes we need at worst case compression. * * LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN */ #define LOWPAN_IPHC_MAX_HEADER_LEN (2 + 1 + LOWPAN_NHC_MAX_ID_LEN) +/* Maximum worst case IPHC header buffer size */ +#define LOWPAN_IPHC_MAX_HC_BUF_LEN (sizeof(struct ipv6hdr) + \ + LOWPAN_IPHC_MAX_HEADER_LEN + \ + LOWPAN_NHC_MAX_HDR_LEN) /* * ipv6 address based on mac diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c index 78c8a495b571..dd5f27d5358e 100644 --- a/net/6lowpan/iphc.c +++ b/net/6lowpan/iphc.c @@ -429,7 +429,7 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, { u8 tmp, iphc0, iphc1, *hc_ptr; struct ipv6hdr *hdr; - u8 head[100] = {}; + u8 head[LOWPAN_IPHC_MAX_HC_BUF_LEN] = {}; int ret, addr_type; if (type != ETH_P_IPV6) -- 2.30.2